The present invention generally relates to a system for supporting and transferring at least a first panel from a first location to a second location, and in particular, to a system for supporting a first panel and for transporting the first panel through a panel processing system.
Aluminum barrels (e.g., cylinders) are weldable to domes (e.g., hemispheres) to make launch vehicle propulsion (e.g., propellant or fuel) tanks. Such barrels may be made from four 90xc2x0 curved panels that are weldable together along longitudinally extending seams in a vertical weld fixture or tool. Generally, for purposes of welding the panels to form a tank, the panels may be placed on a horizontal turntable of the vertical weld fixture and then rotated into clamping bars of the vertical weld fixture. Thereafter, a two torch-single pass/variable polarity gas tungsten arc system may be used to butt-weld the panels together. For a four panel fuel tank, this process is repeated four times to produce a complete barrel.
Prior to butt-welding a first panel to a second panel, the panels are typically transported from a loading area to one or more preparation areas, manually prepared (e.g., cleaned and sanded by hand) at the preparation area(s) in order to enhance the weld, and additionally moved from such panel preparation areas to the weld fixture. Current practices for both manually preparing and moving panels can be labor intensive, time consuming, expensive and inefficient.
In one aspect, the present invention is directed to an automated panel transfer and processing system. More specifically, the system of the present invention is capable of queuing, handling and processing a plurality of aluminum alloy panels (e.g., four panels) which are to be welded together to form a cylindrical portion of a propulsion (e.g., fuel or propellant) tank for use in launch vehicles. In this regard, the system of the present invention is capable of queuing and transporting at least a first panel through at least a first weld preparation station which functions to (1) clean inner and outer edge wall portions (e.g., weld lands) of at least the first panel and to (2) remove a layer comprising aluminum oxide therefrom. Thereafter, the system functions to transport at least the first panel into a weld fixture, where the side edge wall of the first panel may be trimmed (e.g., routed) and then butt-welded to another panel (e.g., a second panel) which has been transferred and processed by the system of the present invention. This system reduces costs and risks associated with manual handling and manual weld land preparation processing. In this regard, panel handling and weld land processing are now controlled and repeatable processes. The successful automation of this process in accordance with the system of the present invention reduces cycle time substantially while also reducing total labor costs and avoids extra costs by reducing the possibility of rework and risk of damage.
In another aspect, the present invention is directed to a digital radiographic weld inspection system for use on the weld fixture. As noted hereinabove, the weld fixture is vertically oriented, and includes a router for trimming side edge walls of at least the first panel to remove aluminum oxide therefrom, and a two torch-single pass/variable polarity gas tungsten arc system for butt-welding the first panel to a second panel processed in accordance with the present invention. Of importance, the vertical weld fixture further includes the digital radiographic weld inspection system. The weld inspection system, which is mountable onto the weld fixture, such that the weld inspection system can inspect welds upon completion of butt-welding operations, includes a fiber optic scintillator (FOS) x-ray to light conversion screen coupled to a high resolution charged coupled device (CCD) camera to produce radiographic images of a weld area between welded panels of the cylindrical fuel tank (e.g., first and second panels). This non-film system allows images of the weld to be viewed immediately upon acquisition on a CRT monitor and eliminates development of film, which results in simplified image review, storage and retrieval of radiographic records. As such, the system provides very fast image acquisition and electronic image enhancements not available with conventional film techniques. Moreover, the barrel welds can be radiographically inspected immediately upon completion of the weld while the panels (e.g., first and second panels) are still clamped in the weld fixture (e.g., full length weld inspection results within 75 minutes of weld completion). This allows improvements in the weld process, with attendant reduction of weld defects and weld repairs since each weld (e.g., weld connecting first and second panels) may be inspected prior to proceeding with the next weld (e.g., weld connecting second and third panels). Accordingly, weld parameters may be adjusted prior to starting another weld, thereby eliminating recurring weld problems. Additional benefits include reduced build cycle-time for assembling a launch vehicle propulsion (e.g., fuel or propellant) tank and reduced labor costs associated with re-installing a barrel into the weld fixture for a full length weld repair if required.